Introduction:Chronic suppurative otitis media (CSOM) is considered one of the most common causes of acquired hearing impairment in developing countries. CSOM is a multifactorial persistent inflammatory disease of the middle ear. A distinct pathophysiologic mechanism linking allergic rhinitis (AR) and CSOM remains to evolve. The purpose of this study was to investigate the association between AR and CSOM in adults.This was a case-control study. Materials and Methods: The subjects were 62 adults (23 male, 39 female) with established CSOM and 61 healthy controls.CSOM was diagnosed when there was a history of chronic (persisting for at least 3 months) otorrhea, accumulation of mucopurulent exudates in the external auditory canal or middle ear and/or perforated tympanic membrane on otoscopy. All participants were evaluated for the presence of AR by clinical evaluation of allergic symptoms, and underwent a skin-prick test for 23 common regional allergens. Statistical analysis was performed using SPSS version 16. Results:The prevalence of clinical rhinitis (allergic and non-allergic) was significantly higher among the cases compared with controls (62.5% vs. 37.5%, P=0.02). The prevalence of AR (proven by positive skin-prick test) was also significantly higher among affected adults than controls (24.6% and 13.8%, respectively). Adjusting for age, a logistic regression model showed that there was a significant difference between the two groups. Patients with AR and non-AR were at 3.27- (95% CI=1.15–9.29; P=0.036) and 2.57-(95% CI=1.01–6.57; P=0.048) fold increased risk of developing CSOM, respectively, compared with healthy individuals. Conclusion:The study showed a higher prevalence of AR in CSOM patients than in controls. It may be valuable to evaluate and control this factor in these patients.